import re
report = '''
If you invested $1 in the year 1801, you would have $18087791.41 today.
This is a 7.967% return on investment. 
But if you invested only $0.25 in 1801, you would end up with $4521947.8525.
'''
#用正则表达式找出所有以$开始的数字，以列表形式返回。
def calc():
    return None

def test_calc():
    assert calc() == ['$1', '$18087791.4', '$0.2', '$4521947.8']
